Preheat oven to 350 degrees F (180 degrees C). Grease an 11x7x2-inch pan.,Melt 1 cup butter in a large saucepan. Add 2 cups light brown sugar and beat well to mix. Cool the mixture slightly, then beat in eggs and vanilla.,______,Spread batter into prepared pan and bake for 30-35 minutes or until a light gold. Cool in the pan for 10 minutes, then turn out of pan and let brownies finish cooling on a rack.,To Make Frosting: Dissolve coffee in the water. Cream 1/2 cup butter with confectioner's sugar. Beat it until light. Blend the coffee into sugar mixture and spread frosting over the brownies. When frosting has set, cut brownies into squares. Enjoy!